Mixed zeolite-containing SCR catalyst
AssigneeBASF Mobile Emissions Catalysts LLC
InventorYuejin Li
Life of this patent
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Abstract
The present disclosure generally provides selective catalytic reduction (SCR) catalyst compositions, catalyst articles and catalyst systems including such catalyst articles for treating engine exhaust gas. In particular, the SCR catalyst composition includes a first zeolite and a second zeolite and has not been subjected to temperatures above 650° C. The first zeolite includes a promoter metal and has a first framework structure and at least a portion of the second zeolite is in a form selected from H+ form, NH4+ form, alkali metal form, alkaline earth metal form, and combinations thereof and has a second framework structure. The first framework structure and the second framework structure are different.
Claims13
A catalytic article comprising a substrate having a plurality of channels for gas flow and a catalyst composition disposed on the substrate, wherein the catalyst composition comprises:
- a first zeolite with a first framework structure and a second zeolite with a second framework structure,
- wherein the first zeolite comprises a promoter metal with a promoter metal content in an amount from about 0.1 to about 50 % by weight based on a total weight of the catalyst composition;
- wherein the first and second framework structures are different and the first or the second framework structure is selected from a small pore framework structure,
- wherein the promoter metal is selected from Cu, Co, Ni, La, Mn, V, Ag, Ce, Nd, Mo, Hf, Y, W and combinations thereof,
- wherein the second zeolite is substantially free of transition metal and is in H′ form, wherein the catalyst composition has a total loading of the first zeolite on the substrate from about 0.1 to about 6 g/in3, and
- wherein the catalyst composition has total loading of the second zeolite on the substrate from about 0.05 to about 1 g/in3.
Dependencies are inferred from the claim text.